We use a unique methodology for collecting this data. We collect data from the browsers of site visitors to our exclusive on-demand network of live stats customers. The data is compiled from approximately 160 million visitors per month. The information published is an aggregate of the data from this network of hosted website statistics. The site unique visitor and referral information is summarized on a monthly, weekly, daily and hourly basis.

In other words, their metrics are based on their own site traffic.

Metrics shown by other sites such as Netcraft are more plausible since they spider the Web looking at Web server signatures.

To my knowledge, the OpenBSD project does not track the number of downloads from the various mirror sites. So outside of CD sales (which supposedly has been down according to information posted on misc@...), there is no other credible manner available for measuring marketshare, although some may use various assumptions & heuristics.

While the target of other Unix-like operating systems may be world/market domination, the target audience of the OpenBSD developers is themselves. So while the developers make the operating system freely available to the rest of us, they are primarily motivated to meet their own needs. Becoming "popular" amongst the technorati simply isn't a high priority.

It is likely that OpenBSD will always remain a small project. It appears that the developers are quite happy with this status quo.